fustian

Fustian has been used in English for a kind of cloth since the 13th century, but it didn't acquire its high-flown sense until at least three centuries later. One of the earliest known uses of the "pretentious writing or speech" sense occurs in Christopher Marlowe's play Doctor Faustus when Wagner says, "Let thy left eye be diametarily [sic] fixed upon my right heel, with quasi vestigiis nostris insistere," and the clown replies, "God forgive me, he speaks Dutch fustian." The precise origins of the word fustian aren't clear. English picked it up from Anglo-French, which adopted it from Medieval Latin, but its roots beyond that point are a subject of some dispute.